Activity of the Sicilian volcanoes during September 2010

ETNA

During the month of September 2010, Etna has continued to show signs of unrest. Sporadic, isolated ash emissions caused by collapse and/or explosions occurred from the active western pit (BN-1) of the Bocca Nuova, the westernmost of the four summit craters of Etna; many of these events were not visible due to inclement weather conditions. Thermal images recorded by the Montagnola monitoring camera, when there was good visibility, revealed no hot material in the emissions, and no ash falls were observed in populated areas.

Throughout the month, deep-seated explosions within the open inner pit on the floor of the Northeast Crater have continued, producing loud booms and prolonged rumbling and hissing sounds, which were well audible during visits to the summit made by INGV-Catania staff and the Etnean mountain guides. Field observations revealed that no new eruptive products have been emplaced, neither outside nor within the visible portion of the Northeast Crater. However, the seismic signals produced by this activity showed a slight increase in amplitude toward the end of the month.

The second half of September was characterized by a significant increase in visible gas emission from the collapse pit on the lower eastern flank of the Southeast Crater cone. During windstill weather, the gas plume rose several hundred meters vertically before being driven downwind at higher altitude, forming a trail tens of kilometers long. A few minor ash emissions, caused by collapse of the unstable walls of the pit, were observed in mid-September. Most of this increased gas emission occurred from a newly formed vent lying at the base of the steep western face of the pit. Profuse steaming also occurred from an extensive fumarole field on the upper eastern flank of the Southeast Crater cone.

STROMBOLI

Stromboli volcano is in a state of persistent eruptive activity, normally with explosions of medium to low intensity occurring from a number of vents located within the summit crater. During the month of September 2010, the activity showed the typical fluctuations characterizing the activity of Stromboli.

VULCANO

Vulcano volcano is currently in a state of quiescence. During the month of September 2010, no anomalies were observed in the geochemical parameters of the peripheral areas (soils in the Vulcano Porto areas and thermal aquifers).